On light to medium pistol loads a .2gr difference is not a problem. Most can't shoot well enough to notice any accurcy issues. .5 probably won't effect such loads much.
On small lots of ammo I often use a 45ACP case trimmed to dip 8.5 grs of Unique for my light 44 mag loads. I can dip with in the .2 gr .
On powder baffles for measures I find an old pill bottle that is a slip fit in the hopper. Cut it about an inch up from bottom. Drill a 1/4 inch hole in center of bottom. If you think that won't flow enough powder fast enough try two holes, one on each side.
This has cut my 55's variations on all powders to small to matter.
Leo